Using the Bag Container

You use a Bag container to indicate that a property has multiple, although unordered, values. How do you specify the multiple items in a container? You use the <rdf:li> element ( modeled after the HTML <LI> , list item, element).

Here's an example: In this case, I'm indicating that the planets.html resource has multiple subjectsMercury, Venus, Mars, and Earth:

Listing ch18_10.rdf

 <?xml version="1.0" ?> <rdf:RDF     xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"     xmlns:dc="http://www.purl.org/DC#">     <rdf:Description about="http://www.starpowder.com/planets.html">         <dc:Title>Planets</dc:Title>         <dc:Creator>Nicolas Copernicus</dc:Creator>         <dc:Type>text</dc:Type>  <dc:Subject>   <rdf:Bag>   <rdf:li>Mercury</rdf:li>   <rdf:li>Venus</rdf:li>   <rdf:li>Earth</rdf:li>   <rdf:li>Mars</rdf:li>   </rdf:Bag>   </dc:Subject>  </rdf:Description> </rdf:RDF> 

The items in a Bag container can also be resource references, of course, like this:

Listing ch18_11.rdf

 <?xml version="1.0" ?> <rdf:RDF     xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"     xmlns:dc="http://www.purl.org/DC#">     <rdf:Description about="http://www.starpowder.com/planets.html">         <dc:Title>Planets</dc:Title>         <dc:Creator>Nicolas Copernicus</dc:Creator>         <dc:Subject>  <rdf:Bag>   <rdf:li   rdf:resource="http://www.starpowder.com/mercury.html"/>   <rdf:li   rdf:resource="http://www.starpowder.com/venus.html"/>   <rdf:li   rdf:resource="http://www.starpowder.com/earth.html"/>   <rdf:li   rdf:resource="http://www.starpowder.com/mars.html"/>   </rdf:Bag>  </dc:Subject>     </rdf:Description> </rdf:RDF>